Three sig figs, the leading zeros are not sig figs
Answer: The partial pressure of oxygen in the mixture is 321 mm Hg
Explanation:
According to Dalton's law, the total pressure is the sum of individual pressures.

Given :
= total pressure of gases = 752 mm Hg
= partial pressure of Helium = 234 mm Hg
= partial pressure of nitrogen = 197 mm Hg
= partial pressure of oxygen = ?
Putting in the values we get:


The partial pressure of oxygen in the mixture is 321 mm Hg
Answer:
About 90 percent of water in the atmosphere is produced by evaporation from water bodies, while the other 10 percent comes from transpiration from plants. There is always water in the atmosphere.✌️